Process and apparatus for producing luminous effects



Sept. 17, 1929. FANGER 1,728,234

PROCESS AND APPARATUS FOR PRODUCING LUMINOUS EFFECTS Filed April 18,1927 f4? ATTOQNEV Patented Sept. 1?, i929 nrrso sT rarer cranes HE J.RANGER, F OAKLAND, CALIFORNIA, ASSIGNOB, BY DIRECT AND MESNEASSIGNMENTS, 0F ONE-THIRD TO EDMUND B. WEEK, JR, MD ONE-THIRD EDMUND B."WEEK, SR., BOTH 0F @AKLAND, CALIFORNIA IPEOCESS AND FOR PRODUCINGLUMINOUS EFFECTS Application filed April 18,

This invention relates to the production of luminous effects byelectrical currents passing through rarefied gases. These efi'ects havebeen noted a long time ago by Geissler,

5 who is popularly credited with their discovery. In his experiments,use was made of rarefied air; but more recently, it has been found thatother kinds. of gases produce highly desirable effects. For example,some of the rare gases occurring in air, such as neon, argon and heliumhave been used to secure brilliant color effects; as well as mercuryvapor. .In all these forms it has been necessary to impress highvoltages across the electrodes of the tube, of the order of 15,000volts, in order to secure a luminous flow of current that could be usedfor forming words, letters or borders inadvertising, and for otherpurposes.

The cost of advertisin equipment using these tubes is rather hig due tothe use of the high voltage, and also to the careful construct1on of theelectrodes forming the terminals of the luminous discharge. It has beenfound that the length of the tube cannot be increased beyond a definitevalue if the luminosity is to persist. This means that a pair ofelectrodes are needed for each unit of length. It is one of the objectsof my invention to make it possible to reduce the number of electrodesthatis needed for a given pattern traced by tubes strung out one afterthe other.

In the past is has also been customa to as secure an even, invariantlight, such as Inc or red. It is another object of my invention to makeit possible to secure a rainbow efiect in the tube, in which there is aconstant/interplay of colors, streaming through the tube in succession.In this way, a much more attractive display is secured than could beobtained in the ordinary type of 'tube.-

My invention possesses many other advantages, and has other objectswhich may be 4 made more easily apparent from a consideration of severalembodiments of my invention. For this purpose I have shown a few formsin the drawings accompanying and forming part of the presentspecification. 'I shall now proced to describe these forms in detail,

1927. Serial No. 134,711.

which illustrate the general principles of my lnventlon; but it is to beunderstood that this detalled description is not to be taken in a l mitng) sense, since the scope of m invention is est defined by the appendeclaims.

Referring to the drawings:

Figure 1 is a schematic diagram showing one form of my luminous tubesystem; and F1g. 2 IS a diagram of another form of my inventlon. so

In Fig. 1 I show a tube 11, partly broken away (to indicate that itslength is indefmite), through which a luminous stream is caused to flow.This tube can be formed into lettersor parts of letters in thewell-understood manner. It has threeelectrodes-two end electrodes 12 and13, and a center electrode 14. All three are sealed in the glass wallofthe tube. Both end electrodes 12 and 13 are connected to one side of ahigh tent1al source, such as the negative si h and the central electrode14 is connected to the other side. The electric current in tube 11 thusflows in two directions from electrode 14, towards the ends of the tube.

The high potential of the source is impressed on each half oftube 11therefore this tube can be made twice as lon as those using onlytwo-electrodes. It is t us possible to use only three electrodes insteadof four, for a pattern double the length of the maximum tube length,with an obvious saving.

The three electrode tube is also advantageous for another urpose. Sinceboth ends of the tube are a ways at the same po-' 35 tential, it ispossible to ass rarefied gas through the tube from end to end, withoutdanger of forming a wasteful byass for the current through gas thatexten s out of the tube and between its ends. I have found that abrilliant display of changing hues can be obtained by causing a constantstream of gas of varied composition to pass through the tube 11.For'example, I mix an inert gas such as neon with small proportions ofmercury vapor, or chlorine, or nitrogen, and successively pass thesevarious mixtures through the tube 11; these various mixtures are thensucked by a vacuum pump to maintain the desired degree of rarefaction,and

the inert gas is purified and passed back to the original storage space.

One mechanism for accomplishing this process is merely. schematicallydisclosed; but obviously other forms can be used; or in fact, theprocess can be produced manually. A container 15 serves as a reservoirfor an inert gas which forms the base of all of the gas mixtures used inthe device. Furthermore, there are a plurality of other containers, 16,17, 18, 19, 20, which can be smaller than container 15, and which holdthe gases used for the mixture. jSuch gases can be chlorine, nitrogen,mercury vapor, or the like, whicheither independently pro duce difierentcolored effects, or do so in conjunction wth the inert gas fromcontainer 15. The mercury container 16 can be heated as by coil 21 toproduce the desired mercury-vapor...

The mechanism 22 can be used for mixing the gases. It can consist of arotary valve member 23 or other distributing valve or valves which isdriven at any desired .speed so as to permit gas from container 15 topass successively through the containers 16 to 20. Thus a manifold 24connects one side of .each container with the outlet of container 15;the other side of each container leads to any air tight. cylinder 25 inwhich valve23 rotates. This valve has a radial opening 26 sweeping pastthe various container outlets, and serves to pass the gas axiallythrough bore 27 and conduit 28 to one end of tube 11'. It is evidentthat as valve 23 rotates, the inert gas from con-, tainer 15 passes insuccession'through the various containers 16 to 20 to take up a smallportion of gas from them. The current in passing throu h these gases ofvarying composition, pr uces a vari-colored effect.

The gases pass through the tube and through a suitable pump 29, providedfor maintaining the gases at the desired low pressures. Thence the gasespassthrough the purifier 30, where the gas content taken fromcontainers'16 to 20 is absorbed or otherwise eliminated. The purifiedinert gas then passes back-into container 15.

It is difiicult ad uately to describe the; color efiects produce by thisform of tube.

There is a constant succession and blending of colors, with 'abrilliance that can be compared with that of a rainbow. 'These colorstravel. through the tube 11, the speed depending upon the speed of themixer mechanism 22. Since both ends of tube 11 are at the samepotential, no current can be shunted wastefully through the mixermechanism 22 andthe ump 29.

Although it is possib e to provide a mixer 22 for each tube 11 that isused in a complete assemblage or sign, yet I can make the mixer performits function for a plurality of tubes This is possible by inserting a;dis-

tributor valve 31 or other distributing valve or valves in the line tothe tube intake. This distributor has a rotary valve element-32 thatserves to connect any one or a few of the total number of tubes such as11 with the conduit 28., The mechanism ismerely diagrammaticallyindicated; it is shown as used to render any combination of. themactive, one tube at least, out of the series of tubes, although notnecessarily the same one, being energized for all switching positions.In this way, various color combinations can be secured,.since but threeprimary colors are needed to obtain all colors of the spectrum. I

The mode of operation of my invention is self-evident from theforegoing. Variations in composition of the gas in the tube 11 areeffected, either at a rapid rate or at a slow rate; and in so doin thedesired color play is obtained by t e passage of current through thegases. V aryin'g efiects can also be made by varying the density of theelectric current supply.

I claim: y

1. The process of obtaining vari-colored luminous efiects, whichcomprises assing a rarefied gas of varying composition through a tube,and applying a suitable high potential across at least a portion of thespace in the tube.

2. he process of obtaining vari-colored luminous efiects, whichcomprises passing a rarefied gas having varying constituents through atube, and appl g a'suitable high potential across at ldd st a portion ofthe space in the tube.

3. The process of obtaining'vari-colorecl luminous efiects, whichcomprises mixing an inert gas with one or more constituent gases,varying the 'constituents 'cyclically,

passing the mixture thus varied through a tube, and applying a suitablehigh potential acggss at least a portion of the space inthe tu 4. Incombination-,atubapeami for pass- -ing a rarefied gas ofavarymgcomposition through the tube, and means for applying a suitable highpotentialacross'at least a portion of the space in the tube.

..;5. In' combination, a tube, means for p'assing a rarefied gas havingvarying constitu;

ents through the tube, and means for applying a suitable high potentialacross at least a portion of the space in the tube.

6. In combination, a tube, means for 5 maintaining a low pressure in thetube, means for electrically energizing said tube, and means for mixingan inert gas cyclically with other gases and for passing said cyclicallyvariable gas through the tube.

10 7. In combination, a tube, means for maintaining a low pressure inthe tube, means for electrically energizing said tube, means. for mixingan inert gas cyclically with other gases and for passing said cycli- 5cally Variable gas through the tube, and means for recovering the inertgas from the mixture after it has passed through the tube.

8. In combination, a series of tubes, a

go mixer for obtaining a current supporting gas of varying constituents,a distributor for passing said gas to said tubes in succession, andmeans for energizing said tube. 9. In a luminous tube device, a tube,

25 means for electrically energizing said tube, and means for passing ararefied gas capable ofbluminescence, continuously through the tu e.

In testimony whereof I have hereunto :20 set my hand.

HERMAN J. FANGER.

